| 摘要 |
865,200. Bolts. FORMAN, B. G. Nov. 27, 1959, No. 40325/59. Classes 89(1) and 89(2). [Also in Group XXII] A self-tapping-screw comprises a metallic-core 11, Fig; 3, in which a metal-member having a screw-thread 14 and a polygonal-shank 42 is inserted, the other end of the core having an insulated-plug 13 with a similar shank 36 therein, the core being surrounded by a threaded moulded-casing 12 of a synthetic-resinousmaterial. The thread 14 is engaged with the casing 12 to form a continuous-thread. In a modification, the screw-threads 127, Fig. 8, are integral with a core 119, which is knurled on its periphery, and has a head 114 with grooves 133 thereon, the outer-casing 112 being keyed to the core by these means. The slot 116 may be single or of cruciform-shape, and the head 114 may be of a more flattened-shape. |
